On January 31, 1970, during operations against enemy forces in the Republic of Vietnam, Private First Class Raymond "Mike" Clausen, Jr., serving with Marine Medium Helicopter Squadron 263, Marine Aircraft Group 16, First Marine Aircraft Wing, took part in a helicopter rescue mission to extract elements of a platoon that had inadvertently entered a minefield while attacking enemy positions. He skillfully guided the helicopter pilot to a landing in an area cleared by one of several mine explosions. With eleven Marines wounded, one dead, and eight others holding their positions for fear of detonating more mines, he leaped from the helicopter and, under enemy fire, crossed the hazardous mine-laden area to help carry casualties to the aircraft and place them aboard. Despite the constant threat of further explosions, he left the comparatively safe area of the helicopter six separate times to continue the rescue. During one of these efforts, while he was carrying a wounded Marine, another mine exploded, killing a corpsman and wounding three other men. Only after he was certain that all Marines were safely aboard did he signal the pilot to lift the helicopter.